Try this:

aggregate(. ~ sample, x[-2], FUN = mean)

On Fri, Mar 11, 2011 at 6:32 AM, Aline Santos <alinexss@gmail.com> wrote:

> Hello R-helpers:
>
> I have data like this:
>
> sample    replicate    height    weight    age
> A    1.00    12.0    0.64    6.00
> A    2.00    12.2    0.38    6.00
> A    3.00    12.4    0.49    6.00
> B    1.00    12.7    0.65    4.00
> B    2.00    12.8    0.78    5.00
> C    1.00    11.9    0.45    6.00
> C    2.00    11.84    0.44    2.00
> C    3.00    11.43    0.32    3.00
> C    4.00    10.24    0.84    4.00
> D    1.00    14.2    0.54    2.00
> D    2.00    15.67    0.67    7.00
> D    3.00    15.11    0.81    7.00
>
> Now, how can I calculate the mean for each condition (heigth, weigth, age)
> in each sample, considering the samples have different number of
> replicates?
>
>
> The final matrix should look like:
>
> sample    height    weight    age
> A    12.20    0.50    6.00
> B     12.75      0.72      4.50
> C     11.35      0.51      3.75
> D     14.99      0.67      5.33
>
> This is a simplified version of my dataset, which consist of 100 samples
> (unequally distributed in 530 replicates) for 600 different conditions.
>
> I appreciate all the help.
>
> A.S.
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

